Shovel won't idle

[Thatguyshawn]

I've got a 76 FLH I'm working on

98" Stroker,
S&S heads,
Super G
Dyna S ignition
Vtwin Mfg. Air filter, carb bowl is vented

I can get the engine to fire up and "run" with either higher rpms constant throttle or lower rpms with blips of the accelerator pump. It will not settle into an idle at all, it doesnt attempt to idle, it just dies if I quit twisting the throttle.

I've recently cleaned/rebuilt the carb(disassembled body/soaked in cleaner), I have reset my ignition timing. I have a complete jet kit, I've reset the carb back to S&S recommended baselines for a 98" engine. I also did pushrod adjustments as well. I dont know where else to look, or what to even think.

I've not seen this bike run since I was a little kid, it was partially disassembled when I inherited it. The heads/jugs look new.

I flushed the gas from the bowl/line and filled up the tank with gas/seafoam and ran that into the carb and am hoping it dissolves a blockage or something.

Any ideas? This is my first shovel so I know jack shit about these things. I'm not without mechanical skill, but I'm just chasing my tail currently.

[Tattooo]

Intake leak???????? Is the carb rebuilt????? What does the plugs look like???? Way more info needed.......

[Tattooo]

Any ideas? This is my first shovel so I know jack shit about these things. I'm not without mechanical skill, but I'm just chasing my tail currently.

Do you have a manual???? Your first Shovel means NOTHING........ A motor is a motor.....

[JBinNC]

This motor should have orings to seal the intake manifold to the heads. If it has bands, replace them now, or if it is possible to fit orings, do so.

Check the mechanical advance unit for wear or broken springs.

Do a compression test (throttle open) so you know what you are dealing with.

Go back and examine the intermediate jet and the idle circuit in the carb to be sure they pass fuel. A can of carb cleaner is a useful tool here, but WEAR GLASSES.

Jim

[Tattooo]

To rebuild a carb correctly it needs to be taken completely apart and soaked over night............

[Thatguyshawn]

This motor should have orings to seal the intake manifold to the heads. If it has bands, replace them now, or if it is possible to fit orings, do so.

Check the mechanical advance unit for wear or broken springs.

Do a compression test (throttle open) so you know what you are dealing with.

Go back and examine the intermediate jet and the idle circuit in the carb to be sure they pass fuel. A can of carb cleaner is a useful tool here, but WEAR GLASSES.

Jim

I did notice a lack of orings on the intake when I had the heads off,i did new head gaskets and bolts, torqued per manual. I'll hit the indie shops tomorrow to see if I can get a whole new band/clamp/oring set. I havent found a solid answer on what is required for the taller jugs and matching intake.

The passages in the carb can pass air, I've checked from the idle mix screw hole, and get air at the intermediate jet. The main and intermediate jets are both new out of the jet kit. The bowl vent isnt plugged by my filter assembly so I've left the vent screw on the carb body in.

When I cleaned the carb I disassembled and let it soak for 6 hours or so, then blasted everything with carb cleaner and air before reassembly. It wasn't particularly dirty with any varnish or anything on initial dissambly. All new gasket/orings throughout.

I'll do a compression check for reassurance, but she definitely has compression.

[Tattooo]

I did notice a lack of orings on the intake when I had the heads off,

So you don't have any Orings at all on the intake?????

[Thatguyshawn]

So you don't have any Orings at all on the intake?????

It may be dumb, I thought it was weird myself, I don't know though. With all the aftermarket shit specifically related to the intake seals, i went with how i received it. I've never toyed with older bikes and am learning as I go between the manual, how it was put together when I received it, and any research I can about the parts I've found on it.

I'll buy any parts that are crucial, I'm not trying to be cheap, I'm just trying to return this bike back to road worthy.

[markwade74]

They're pretty crucial, buy some

[JBinNC]

It may be dumb, I thought it was weird myself, I don't know though. With all the aftermarket shit specifically related to the intake seals, i went with how i received it. I've never toyed with older bikes and am learning as I go between the manual, how it was put together when I received it, and any research I can about the parts I've found on it.

I'll buy any parts that are crucial, I'm not trying to be cheap, I'm just trying to return this bike back to road worthy.

Your '76 motor should have orings for intake seals, but since the heads have been replaced with S&S heads, it could be that the heads are cut for orings or bands. The intake manifold should be cut the same way, but a mix of parts is not unusual on these old motors. For a 98cu.in. shovel built in the usual way with .200" taller cylinders, you need a wider intake manifold to fit well between the heads. The older S&S manifolds were marked with a number to denote the size, and a #3 would be the usual size for a 98.

A head intake spigot or an intake manifold that is cut for orings will have a step about 3/32 wide and 3/16 deep to accept an oring when the head and manifold are mated. Then a clamp is fitted over the oring and tightens securely to the head and manifold. This set-up is pretty foolproof as long as the heads are positioned for a good fit to the intake.

A head and manifold cut for bands have a smooth spigot with no step. In this case, a rubber band seal fits over head and manifold, and a clamp fits over the rubber band. This is not as secure, and REQUIRES a carb brace of some sort. These bands are more likely to leak, creating a vacuum leak. The clamps must be in good shape and tightened carefully to prevent leaks.

Orings or bands are used, not both. It is possible to fit an oring manifold to band heads, using bands, or vice versa. Orings can only be used if both head and manifold are cut for them. They give the best seal.

Jim

[Dragstews]

Orings can only be used if both head and manifold are cut for them. They give the best seal.

Jim

Now I wouldn't say dat !!

[JBinNC]

Now I wouldn't say dat !!

Deep in your heart of hearts you know it's true. The orings last for YEARS with no leaks. Bands service life is MUCH shorter. And you know it.

Jim

[Dragstews]

I take it you never used a set of these ....


You'll change your tune after ya do ....

[JBinNC]

I take it you never used a set of these ....


You'll change your tune after ya do ....

Still won't last as long as the orings, sorry.

Jim

[Dragstews]

They are not made from Rubber that the Mo-Co used back in the day ....

Ya gotta come out of the cave to see what's new every now and again ...